JP Hei09(1997)-120323 A discloses a technique for reducing power consumption according to the use condition of the electronic device. According to JP Hei09(1997)-120323 A, a line of sight of a user is detected from an image obtained by picturing the user using the electronic device and the tilt of the electronic device is detected, and the power supply of the electronic device is controlled depending on the detected parameters. More specifically, according to JP Hei09(1997)-120323 A, if the line of sight of the user is not in the direction of the electronic device and the electronic device has been tilted by a certain amount or more for a certain period of time or longer, power supply to the display control unit of the electronic device is stopped and the backlight is turned off. That is, according to JP Hei09(1997)-120323 A, an image is displayed when the user is viewing the display screen, and no image is displayed when the user is not viewing the display screen.